Process for casting metals.



M. v. SMITH.

PROCESS FOR GASTING METALS. APPLICATION FILED APR. 5, 1907.

Patented Mar. 9, 1909.

INVFELX h TORNEYSC Y WITNESSES: 9 5

UNITE PATEN OFFICE.

:marnv v. sMrrn,- or NEWYoaK, N. Y.

N's. (#144379.v

To all it may camera; "Be it knownthat 'I, MARTIN VAN BUBEN SMITH, a citizen of theUnited States of Amer- .15' 'around a core of other metal such as iron or Q ceive it, such copper 1n coo steel which has been properlypflepared'to reg contracts around the coreand is caused to adhere. so-

- I I closely to the surface thereof as to cause the' 20.

two metals to be practically one. The adhe sion appears to be a mechanical one dueto thefcopper entering minute interstices .0011- v tained inthe core, so thatthere is virtually a bonding'between the two metals, which, if

pro er1'y.- effected, makes them inse arable,

i an enables the product asa who e to be treated'as if it were one-integral piece of metal. -An iron or steel, core covered with vcopper in this waymay be rolled and drawn down to fine wire, but the proportion of co .p er and core is substantially maintained.

he success of thisprocess is necessarily dependent u on the. union between the. two

i metals, an to insure this proper union, the

surface of; the core is first treated by being rendered as smooth as possible, then cleaned so as to remove any surface dust, and is finally treated with a chemical whereby every trace of grease is removed; The cleancold core' forces partic es of copper into the.

mg is conveniently efiected by'a sand blast, thlslcleaning not only the extreme outer surface, but also the exposed pores. The chemical treatment also cleans out the pores as well as the. outer surface, leaving the mate rial in .a' condition to receive the cop e when appliedwith great. pressure. The shrinka e o the molten copper u on the comparative y pores or interstices, as above set forth, with the result that, under the best conditions, union is almost perfect. I have found, however, that the best conditions have been diificult to obtainin'the past, and that perfect seemsthat air has union has not. always resulted even thouglh' the conditions appeared to be ideal. t een locked in between the .Specification of Letters Patent. Application filed April 5, 190:1. Serial it. seem.

iea, and a resident of the. city, county, and

between the m0 hausted t nnoonss non .cns'rnze mavens.

' Patented mm, 1009.

I surface of the core and the shell, thereby preventing adhesion. To air it has been attempte open at the'bottom, into a crucible of copper,

prevent ent app e to plunge a mold,-

whereby the co 3 1. 111. e f rc d new 61 I if lie nd he or xpe l n t i up a d as it ises has only chi iated the trouble to a limited extent forthe reason that the metal rising not force all the air'npward, a thin skin of air seeming to cling to t eface of the core, spite of the metal rising around it. Moreover, the pores themselves also contain more or less air which is not expelled in way. Further.

more, it will be w l underst od, t0 l ngs. m l of a y pth int acru ible Q de scription necessitates the employment of a very deep crueible-with a very large-quantityof molten copper contained therein. is very difficult to keep sucha large mass of molten metal at an even temperature, and while this difiiculty not, perhaps, unsur mountable, it is a very serious one commer cially.

In carrying out my invention I exhaust the air away. from the face of the-core, and apply the molten copper thereto only as the air is exhausted. By this means I get rid'gfnot only the air contained freely around the face of the core, but the air which would'oth erwise cling to the face thereof and be 0.011.-

tained withinthe surface pores is also carried off, so that the core is in an idealv condition to receive the said'v copper with. mold openat the bottom and connected at the top with air exhausting means, I am onabled to utilize atmospheric pressure for lif t.

gopper, and, u on cooling, the 1 form a per ect union theretively small quantity of the molten metal.

[Thespecific gravity of copper being somewhere between 8.5 and 9.0, the'atmosphere' theoretically support-a3 column thereof between three andfour feet in height. enables me to readily e loy-a mold about three feet in depth, whiefi purpose.

Another convenience in the employmentof' my present invention is that, after the l h s be nfi it may-be ted out f th ruc b e w ho t it b g n cessary to close the lower end thereof mechanically, as

is ample for the Again, by mounting the core in a .ing the co per into the mold as theiair is ex,- I

Eerefrom, whereby the mold may be dipped at its lower end into a shallow; crucible such as contains. but a comparathereto by means of a the air pressure will hold up the molten metal contained therein until it has cooled to a point where it will not flow, though the lower end of the mold may be closed after the mold is removed from the crucible, if desired. It

will be understood that in the old wa of casti by plunging the mold into a cop crucib c, it was necessary to close the lower end of the mold before removing the same from the crucible, and this has proved to be a diflicult task and has involved expensive apparatus. a 4

In order that my invention may be fully understood,.I will now proceed to describe a simple form of ap aratus in which the proc ess may be carried out, and also'to describe the process in detail as carried out in such aparatus, and will then point out the novel eatures in claims. Such an apparatus is illustrated in the accompanyingv drawing, the mold and crucible being shown in sectional elevation, and the exhausting appaa ratus in side elevation.

The mold comprises a body portion 1,-- and a cap 2 secured t ereto by bolts 3. -A core 4 is supported by-the cap piece 2, being bolted.

o t 4, which is tapped,

into the core, and which passes throu h the cap 2, and is provided on the outside t ereof with a nut 5. The inside bore of the mold 1 is larger than the outside diameter of the core 4, the space between the mold and core being the s ace for receiving the molten copper, and t e width thereof constituting approximately the. thickness of the shell of copper u on the core when the casting is com leted. e upper cap is provided with a ollow chamber 6 which is connected by means of pi ing or h0se7 with a suction pump? or other e austing ap aratus. The cham er 6 communicates wit the space between the mold and the core throu h minute orifices 9. The orifices. 9 are pre erably so small that the molten copper willnot pass through them, though they be large enou h to permit the dlscharge of all the air. A s allow cruci his 10 is provided, such crucible conta' a mass of the molten material which is to e cast around the core 4.,

In carrying out the process, the moldwith the core therein will .be plunged at its lower end mto the metal contained in the crucible '10, and air 'will then be-exhau sted from the mold, until fina lowed to cool. .The vacuum will pre be, maintained until the copper is pooled sufliciently to cause it to set, or, 1f preferred, the'lower end of. the mold may be) -mechanically closed in the usual manner.

As the cop er contracts it willbe forced into the pores-o the metal core 4, until finally the union between the shell and the core is complate. The. cap and the mold ma now be eed from each other by removal 0 the bolts 1 --3, and the mold removed. The moldw ll readily come away from the shell of copper ave because the contraction thereof will caused the same to shrink away from the inner surface of the mold, as will be well un-' derstood. B removing the not 5, the core with the she of copper thereon may be removed from the 'cap, and the casting process will now be complete. What I claim is: I

1. The herein described process of applying to a core of one metal an outer she another metal which consists in mounting the core in a mold, exhausting the air from the mold and'the surface of the core, and

causing the other metal to flow into the mold around the .core in the same direction the air flows therefrom. 1

2. The herein described process of applyin an outer shell Of copper to, a core .0 a

ot er metal which consists in first preparing the surface of said metal c'ore m such away as to leave the external pores open, in then exhausting the airfrom the surface of the said core, and in then surrounding the core with molten co per-and allowing the co per in a mold having an openbottom, plunging the'b'ottom of the mold into a shallow crucible containing molten copper and exhausting air from the space between. t 1e mold and the outer surface of the core, whereby to remove air from the surface of the core, and to cause the molten copper to be forced upward into the mold around the core by atmospheric pressure.- Y

'4. The which consists in mountings core in a m having an open bottom, plungin the bottom of the mold into a shallow cruci le contain,- ing molten metal, exhausting the air from the mold, whereby to remove airffrom the sur face of the core and to cause the 'molten metal to be forcedupward. into the, mold around the core by atmospheric pressure, and in maintaining the'cast metal in position by atmospheric ressure until. it sets after removing the mo d from the crucible.

M; v. SMITH. Witnesses: v D. Howaan Harwoon, Lmni S. Ammnws, Jr.

herein described process of casting o 

